RESEARCH ARTICLE
Population rate coding in recurrent neuronal networks
with unreliable synapses
Daqing Guo
•
Chunguang Li
Received: 7 February 2011 / Revised: 9 July 2011 / Accepted: 5 November 2011 / Published online: 18 November 2011
Ó Springer Science+Business Media B.V. 2011
Abstract Neuron transmits spikes to postsynaptic neu-
rons through synapses. Experimental observations indi-
cated that the communication between neurons is
unreliable. However most modelling and computational
studies considered deterministic synaptic interaction
model. In this paper, we investigate the population rate
coding in an all-to-all coupled recurrent neuronal network
consisting of both excitatory and inhibitory neurons con-
nected with unreliable synapses. We use a stochastic on-off
process to model the unreliable synaptic transmission. We
find that synapses with suitable successful transmission
probability can enhance the encoding performance in the
case of weak noise; while in the case of strong noise, the
synaptic interactions reduce the encoding performance. We
also show that several important synaptic parameters, such
as the excitatory synaptic strength, the relative strength of
inhibitory and excitatory synapses, as well as the synaptic
time constant, have significant effects on the performance
of the population rate coding. Further simulations indicate
that the encoding dynamics of our considered network
cannot be simply determined by the average amount of
received neurotransmitter for each neuron in a time instant.
Moreover, we compare our results with those obtained in
the corresponding random neuronal networks. Our
numerical results demonstrate that the network randomness
has the similar qualitative effect as the synaptic unreli-
ability but not completely equivalent in quantity.
Keywords Recurrent neuronal network
Unreliable synapse Noise Population rate coding
Introduction
Neuron is a powerful nonlinear information processor in
the brain. By sensing its surrounding inputs, neuron con-
tinually generates appropriate discrete electrical pulses
termed as action potentials or spikes. These spikes are
transmitted to the corresponding postsynaptic neurons
through synapses, which serve as the communication
bridges between different neurons. It is known that the
information processing in the brain is highly reliable.
However, some biological experiments have demonstrated
that the microscopic mechanism of synaptic transmission
displays the unreliable property (Abeles 1991; Friedrich
and Kinzel 2009; Raastad et al. 1992; Smetters and Zador
1996). Such unreliability is attributed to the probabilistic
neurotransmitter release of the synaptic vesicles (Allen and
Stevens 1994; Branco and Staras 2009; Katz 1966; Katz
1969; Trommershauser et al. 1999). For real biological
neural systems, the successful spike transmission rates
between 0.1 and 0.9 are widely reported in the literature
(Abeles 1991; Allen and Stevens 1994; Rosenmund et al.
1993; Stevens and Wang 1995). In the past decades,
several works, though not many, have investigated the
D. Guo
School of Electronic Engineering, University of Electronic
Science and Technology of China, Chengdu 610054,
People’s Republic of China
e-mail: dqguo07@gmail.com
Present Address:
D. Guo
Computational Neuroscience Unit, Okinawa Institute of Science
and Technology, Okinawa 904-0411, Japan
C. Li (&)
Department of Information Science and Electronic Engineering,
Zhejiang University, Hangzhou 310027,
People’s Republic of China
e-mail: cgli@zju.edu.cn
123
Cogn Neurodyn (2012) 6:75–87
DOI 10.1007/s11571-011-9181-x